CDChat: A Large Multimodal Model for Remote Sensing Change Description
This addresses a domain-specific need for remote sensing applications by providing an incremental improvement in change description capabilities.
The paper tackles the problem of describing changes between bi-temporal remote sensing images, a key task where existing large multimodal models struggle, by introducing a change description instruction dataset and finetuning the LLaVA-1.5 model to achieve favorably better performance.
Large multimodal models (LMMs) have shown encouraging performance in the natural image domain using visual instruction tuning. However, these LMMs struggle to describe the content of remote sensing images for tasks such as image or region grounding, classification, etc. Recently, GeoChat make an effort to describe the contents of the RS images. Although, GeoChat achieves promising performance for various RS tasks, it struggles to describe the changes between bi-temporal RS images which is a key RS task. This necessitates the development of an LMM that can describe the changes between the bi-temporal RS images. However, there is insufficiency of datasets that can be utilized to tune LMMs. In order to achieve this, we introduce a change description instruction dataset that can be utilized to finetune an LMM and provide better change descriptions for RS images. Furthermore, we show that the LLaVA-1.5 model, with slight modifications, can be finetuned on the change description instruction dataset and achieve favorably better performance.